Syringe pumps are used in a variety of therapy areas to administer drugs, nutritional compositions, and prescribed fluids or fluid-like substances (collectively, “medicaments”) to patients in volume and time controlled doses. Medicaments can accurately and continuously be administered by such pumps, at infusion rates typically ranging from as little as 0.1 ml/hr. to as much as 1200 ml/hr. Because of their ability to deliver medicaments in a precise, accurate, and continuous manner, syringe pumps are well suited to pain management and palliative care, for instance, and are also often useful in neonatal and pediatric intensive care units.
In operation, a medicament syringe pump includes a syringe having a plunger that slideably, but tightly, fits inside of a cylinder which in turn contains a medicament. Medicament is administered from the cylinder by operation of the pump in shifting the plunger through the cylinder. Medicament is thus expelled from the cylinder under pressure, through a delivery route comprising a needle, nozzle, tubing, or the like, directing the medicament to a patient. Medicament from a syringe in a syringe pump can be administered, for example, intravenously, intra-arterially, epidurally or subcutaneously. As will be appreciated, a constant and metered application of medicament requires a steady and accurate flow from the syringe in the syringe pump through the delivery route. An unexpected increase in the delivery pressure of the pump can indicate a flow blockage, pump malfunction, or other problem.
A force sensor can be placed in communication with a plunger driver head of a syringe pump, as shown, for example, in U.S. Pat. Nos. 7,635,349 and 6,551,277. A build up of pressure beyond normative operating ranges can accordingly be sensed, triggering alarms and initiating corrective action. Generally, sensors of this type are constructed from either thin foil material or a glass substrate that has been metalized, such as a silicon wafer. Particularly in the case of the latter, rough handling or extreme overloads are of concern, in that the sensor can be irreparably damaged, requiring that the pump be taken out of service for repair.
An overload protection method and system for isolating a force sensor in a syringe pump from the damaging effects of rough handling or extreme overloads, yet still enabling the force sensor to accurately, reliably and repeatedly detect overload conditions and/or provide for overload alarms, would provide decided advantages.